Add test to check if persisting a @OneToOne child entity which has @MapsId works when referencing a parent entity

hibernate-core/src/test/java/org/hibernate/test/annotations/onetoone/OneToOneMapsIdTest.java

@@ -0,0 +1,114 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.test.annotations.onetoone;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.MapsId;
+import javax.persistence.OneToOne;
+
+import org.hibernate.annotations.NaturalId;
+import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
+
+import org.junit.Test;
+
+import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Vlad Mihalcea
+ */
+public class OneToOneMapsIdTest extends BaseEntityManagerFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[] {
+				Person.class,
+				PersonDetails.class
+		};
+	}
+
+	@Test
+	public void testLifecycle() {
+		Person _person = doInJPA( this::entityManagerFactory, entityManager -> {
+			Person person = new Person( "ABC-123" );
+			entityManager.persist( person );
+
+			return person;
+		} );
+
+		doInJPA( this::entityManagerFactory, entityManager -> {
+			Person person = entityManager.find( Person.class, _person.getId() );
+
+			PersonDetails personDetails = new PersonDetails();
+			personDetails.setNickName( "John Doe" );
+			personDetails.setPerson( person );
+
+			entityManager.persist( personDetails );
+		} );
+	}
+
+	@Entity(name = "Person")
+	public static class Person  {
+
+		@Id
+		@GeneratedValue
+		private Long id;
+
+		@NaturalId
+		private String registrationNumber;
+
+		public Person() {}
+
+		public Person(String registrationNumber) {
+			this.registrationNumber = registrationNumber;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
+		public String getRegistrationNumber() {
+			return registrationNumber;
+		}
+	}
+
+	@Entity(name = "PersonDetails")
+	public static class PersonDetails  {
+
+		@Id
+		private Long id;
+
+		private String nickName;
+
+		@OneToOne
+		@MapsId
+		private Person person;
+
+		public String getNickName() {
+			return nickName;
+		}
+
+		public void setNickName(String nickName) {
+			this.nickName = nickName;
+		}
+
+		public Person getPerson() {
+			return person;
+		}
+
+		public void setPerson(Person person) {
+			this.person = person;
+		}
+	}
+
+}